Do any of these, pine or cedar, add a ph to the soil that would be bad for the ligularia.

Hosta's grow in the rest of the area.

I bet moisture may be a bigger problem though, since Ligularia needs constant water. Also, Ligularia thrives in my alkaline soil, but I didn't think it thrives because of its alkalinity. So I looked it up. Below it says any ph and any quality of soil. Therefore, if you beat the water problem, it should be ok.

Hope this helps.